Context-based automatic reconstruction and texturing of 3D urban terrain for quick-response tasks     

《ISPRS Journal of Photogrammetry and Remote Sensing》2014

Highly detailed 3D urban terrain models are the base for quick response tasks with indispensable human participation, e.g., disaster management. Thus, it is important to automate and accelerate the process of urban terrain modeling from sensor data such that the resulting 3D model is semantic, compact, recognizable, and easily usable for training and simulation purposes. To provide essential geometric attributes, buildings and trees must be identified among elevated objects in digital surface models. After building ground-plan estimation and roof details analysis, images from oblique airborne imagery are used to cover building faces with up-to-date texture thus achieving a better recognizability of the model. The three steps of the texturing procedure are sensor pose estimation, assessment of polygons projected into the images, and texture synthesis. Free geographic data, providing additional information about streets, forest areas, and other topographic object types, suppress false alarms and enrich the reconstruction results.  相似文献   

Building population mapping with aerial imagery and GIS data     

Serkan Ural  Ejaz Hussain  Jie Shan 《International Journal of Applied Earth Observation and Geoinformation》2011

Geospatial distribution of population at a scale of individual buildings is needed for analysis of people's interaction with their local socio-economic and physical environments. High resolution aerial images are capable of capturing urban complexities and considered as a potential source for mapping urban features at this fine scale. This paper studies population mapping for individual buildings by using aerial imagery and other geographic data. Building footprints and heights are first determined from aerial images, digital terrain and surface models. City zoning maps allow the classification of the buildings as residential and non-residential. The use of additional ancillary geographic data further filters residential utility buildings out of the residential area and identifies houses and apartments. In the final step, census block population, which is publicly available from the U.S. Census, is disaggregated and mapped to individual residential buildings. This paper proposes a modified building population mapping model that takes into account the effects of different types of residential buildings. Detailed steps are described that lead to the identification of residential buildings from imagery and other GIS data layers. Estimated building populations are evaluated per census block with reference to the known census records. This paper presents and evaluates the results of building population mapping in areas of West Lafayette, Lafayette, and Wea Township, all in the state of Indiana, USA.  相似文献   

Building footprint database improvement for 3D reconstruction: A split and merge approach and its evaluation     

Bruno Vallet  Marc Pierrot-DeseillignyDidier Boldo  Mathieu Brédif 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(5):732-742

We present a general framework to improve a vectorial building footprint database consisting of a set of 2D polygons. The aim of this improvement is to make the database more proper to subsequent 3D building reconstruction at a large scale. Each polygon is split into several simple polygons guided by a digital elevation model (DEM). We say that this segmentation is vectorial as we produce segmentations that intrinsically have simple polygonal shapes, instead of doing a raster segmentation of the DEM within the polygon then trying to simplify it in a vectorization step. The method is based on a Mumford and Shah like energy functional characterizing the quality of the segmentation. We simplify the problem by imposing that the segmentation edges have directions present in the input polygon over which the DEM is defined. We evaluate the validity of the proposed method on a very large dataset and discuss its pros and cons based on this evaluation.  相似文献   

湖南省农村房屋安全性现状统计分析   总被引：2，自引：1，他引：1  

赵光超  汪晓丰 《震灾防御技术》2011,6(3):291-299

本文汇总了湖南省农村房屋的安全性等级情况资料,从房屋的建造年代、结构形式、各年代所建房屋的危房率以及居民的住房质量、安全意识与房屋抗震性能的对比几个方面进行了房屋安全性状况统计分析.结合房屋典型损坏现象,分析了此次调查中房屋的损坏特征,总结了各种结构形式容易出现的问题.根据房屋典型损坏现象分析和安全性等级情况统计,得出了以下结论:湖南省农村生土结构和木结构房屋的安全性现状不容乐观;有关部门应制定一套适合农村的结构设计规范,并通过培训等方法解决农村房屋设计和施工问题;部分存在潜在严重地质灾害的地区和大山深处的房屋已无改造、新建的意义,最好整体搬迁.  相似文献   

青海省共和地区农村民居特征与抗震性能分析     

王洪  王成虎  安易飞  陈念  周昊 《震灾防御技术》2021,16(2):315-325

青海省共和地区位于柴达木—阿尔金地震带内,具备发生中强地震的构造背景,近年来该地区地震活动频繁,农村地区受经济和技术等条件的限制,造成了巨大的人员伤亡和经济损失。为深入了解共和地区农村民居结构特征与抗震性能现状,开展实地调查,基于历史震害资料,总结区域内典型农村民居震害特点,并进行震害预测,得到不同地震烈度下农村民居不同的破坏结果。结果表明:青海省共和地区农村民居中的砖混结构和砖木结构房屋数量约占48%、47%,其中约68%砖混结构房屋未设置构造柱和圈梁等抗震设防措施;该地区主要农村民居基本达到Ⅶ度抗震设防要求,仅部分建造年代久的土木结构房屋破坏严重;地震烈度为Ⅷ度时,大部分房屋以中等破坏和严重破坏为主;地震烈度为Ⅸ、Ⅹ度时,农村民居将发生大范围严重破坏,甚至毁坏。  相似文献   

Rectilinear building roof contour extraction based on snakes and dynamic programming     

《International Journal of Applied Earth Observation and Geoinformation》2013

This paper presents a method for extracting building roof contours from digital images collected over urban landscapes. The proposed method utilizes an energy function based on snakes that represents building roof contours in digital images and is optimized with a dynamic programming (DP) algorithm. Because most building roof contours are characterized by rectilinear sides that intercept at right angles, appropriate geometric constraints are enforced in the previously reported snake-based energy function. The main advantage of using the DP algorithm for optimizing the proposed snake-based energy function is its better radius of convergence compared to that typically obtained in the original solution based on variational approaches. Experimental evaluation, which included visual inspections and numerical analyses, was performed using real data, and the obtained results demonstrated that the proposed method has significant potential for successfully extracting building roof contours from digital images.  相似文献   

A comprehensive review of earthquake-induced building damage detection with remote sensing techniques     

《ISPRS Journal of Photogrammetry and Remote Sensing》2013

Earthquakes are among the most catastrophic natural disasters to affect mankind. One of the critical problems after an earthquake is building damage assessment. The area, amount, rate, and type of the damage are essential information for rescue, humanitarian and reconstruction operations in the disaster area. Remote sensing techniques play an important role in obtaining building damage information because of their non-contact, low cost, wide field of view, and fast response capacities. Now that more and diverse types of remote sensing data become available, various methods are designed and reported for building damage assessment. This paper provides a comprehensive review of these methods in two categories: multi-temporal techniques that evaluate the changes between the pre- and post-event data and mono-temporal techniques that interpret only the post-event data. Both categories of methods are discussed and evaluated in detail in terms of the type of remote sensing data utilized, including optical, LiDAR and SAR data. Performances of the methods and future efforts are drawn from this extensive evaluation.  相似文献   

Automatic extraction of building roofs using LIDAR data and multispectral imagery     

《ISPRS Journal of Photogrammetry and Remote Sensing》2013

Automatic 3D extraction of building roofs from remotely sensed data is important for many applications including city modelling. This paper proposes a new method for automatic 3D roof extraction through an effective integration of LIDAR (Light Detection And Ranging) data and multispectral orthoimagery. Using the ground height from a DEM (Digital Elevation Model), the raw LIDAR points are separated into two groups. The first group contains the ground points that are exploited to constitute a ‘ground mask’. The second group contains the non-ground points which are segmented using an innovative image line guided segmentation technique to extract the roof planes. The image lines are extracted from the grey-scale version of the orthoimage and then classified into several classes such as ‘ground’, ‘tree’, ‘roof edge’ and ‘roof ridge’ using the ground mask and colour and texture information from the orthoimagery. During segmentation of the non-ground LIDAR points, the lines from the latter two classes are used as baselines to locate the nearby LIDAR points of the neighbouring planes. For each plane a robust seed region is thereby defined using the nearby non-ground LIDAR points of a baseline and this region is iteratively grown to extract the complete roof plane. Finally, a newly proposed rule-based procedure is applied to remove planes constructed on trees. Experimental results show that the proposed method can successfully remove vegetation and so offers high extraction rates.  相似文献   

Polygon‐based texture mapping for cyber city 3D building models     

F. Tsai  H.‐C. Lin 《International journal of geographical information science》2013,27(9):965-981

The three‐dimensional building model is one of the most important components in a cyber city implementation. Currently, however, most building models do not have sufficient and accurate texture information. The lack of texture not only makes 3D building models less realistic in visualization, it may also fail to provide needed information in intricate applications. This study developed a polygon‐based texture mapping system to produce near photo‐realistic texture mappings for 3D building models. Textures of building exteriors were generated from mosaics of close‐range photographs acquired with commodity digital cameras. The developed system integrated multiple digital photographs to create texture mosaics that were continuous in geometric outlines and smooth in colour shadings, and correctly mapped them onto corresponding building model façades. A test example demonstrated that the resultant building model had more complete and accurate texture features as well as a near‐photo‐realistic appearance.  相似文献   

An analytical model of soil–structure interaction with swelling soils during droughts     

《Computers and Geotechnics》2013

Lightly loaded structures constructed on expansive soils may develop structural damage as a result of changes in the soil’s moisture content. This study investigated an analytical model of soil–structure interaction to assess the settlement of dwellings built on swelling soils when droughts occur. The building behavior was investigated with the Euler–Bernoulli beam theory, and the ground behavior was investigated with a Winkler-derived model based on the state surface approach. The analytical model results were compared to those of a finite element analysis using the Barcelona Expansive Model (BExM) performed with Code_Bright.The analytical model was then used to assess the settlement transmission ratio for a typology of clayey soils and different parameters of building. The results indicated that the final deflection of the building increased with the building length and soil suction. The building deflection due to the suction variations was inversely proportional to the load, the rigidity of the building and the embedding depth of the foundation. Increasing these parameters made the building less vulnerable to shrinkage and swelling action.  相似文献